With the holiday season around the corner, most people may first think of reindeer as Santa Claus’ trusted helpers. But it turns out that reindeer are not only good at pulling Santa’s sleigh; they can also teach us important lessons about the functioning of ecosystems. By studying small meadows in the Swedish mountains, formed by historical traditional reindeer herding practices, Dagmar Egelkraut revealed long-lasting ecological effects induced by reindeer grazing in her doctoral research.